environment

The 7,100 islands of the Philippine Republic, scattered across the Pacific Ocean and South China Sea, teem with life. The entire nation is a recognized biodiversity hotspot — rated among the 17 most mega-biodiverse countries in the world — with rainforests, volcanic mountain ranges and tropical waters known for species found nowhere else on the planet.

The archipelago’s isolation for millions of years, and its wide variety of habitats has contributed to speciation across the island chain’s 300,000 square kilometers (115,831 square miles) of land area.

Species such as the Philippine eagle (Pithecophaga jefferyi), one of the largest in the world, the Sulu hornbill (Anthracoceros montani), of which fewer than 30 are thought to still exist, and the Philippine Mouse deer (Tragulus nigricans), which stands just seven inches tall, live in forests across the archipelago.

A staggering 40 percent of all bird species found in this island nation are endemic — 226 out of 569 species. Compare that to the level of avian endemism in the United States, which stands at just 7.5 percent, even though the US is more than thirty times the size of the Philippines.

BirdLife International has identified ten Endemic Bird Areas (EBAs) in the Philippines — EBAs being “the most important places for habitat-based conservation of birds” worldwide. Together those ten EBAs encompass almost the whole of the archipelago.

But these species-rich habitats, along with the unique animals that rely on them for survival, are at risk due to a legacy of extreme deforestation that is many decades old: only a fraction of primary Philippines forest is left.

Among the most endangered animals are the elusive, shy, ground-dwelling Bleeding-heart doves, named for the colorful red or orange plumage that looks like an open wound blossoming on their white breasts.

All five Bleeding-heart dove species are endemic to the Philippines. Three, found on just a handful of islands, are classified as Critically Endangered by the IUCN. They’ve also been singled out by the Zoological Society of London’s EDGE of Existence program which lists them in the top 100 “Evolutionary Distinct and Globally Endangered” bird species.

Favoring closed canopy lowland forest, and foraging on the forest-floor, Bleeding-hearts are particularly hard hit when the little forest that remains to them is disturbed or cut down.

“Habitat loss from small scale logging, mining and human encroachment (agriculture and residential) are [the] main threats” to the species, revealed Juan Carlos Gonzalez, the Director and Curator for Birds at the Museum of Natural History, University of the Philippines at Los Baños. The birds are also hunted for consumption, trapped accidentally alongside other target species, and captured for sale in the pet trade. This is despite protection under Philippine law for all endangered species, with penalties ranging from fines to several years imprisonment.

For one species, the Sulu Bleeding-heart (Gallicolumba menagei) the chance for survival is slim. Fewer than 50 individuals are thought to remain on the island of Tawitawi. Even though there hasn’t been a confirmed sighting of the species since 1891, reports from the 1990s offer some hope that a small population hangs on.

It’s not only the extreme rarity of G. menagei that makes a comprehensive population assessment difficult. Accessing its most likely habitat to do a thorough survey is hampered by the “risk of bandits and insurgency,” Gonzalez said. Read the full article on Mongabay.

Hydropower development is booming, with controversial projects unfolding across the Americas, Africa, Asia and Europe.

Though often presented as a green renewable energy option, dams can cause a litany of negative impacts: disrupting the downstream flow of nutrients, interrupting aquatic migration routes and harming fisheries. They flood forests, destroy habitat and increase the release of greenhouse gases as vegetation decomposes. Dams also displace human communities — submerging homes and indigenous territories.

A new study adds another impact to the list, one that is widespread but has so far been overlooked by dam developers: “extinction debt” — the incremental but inexorable loss of species and diminishment of biodiversity over time on islands created by reservoirs.

Hydropower developers have long claimed reservoir islands as quality habitat and as viable conservation areas — both assertions are false, according to the new research.

A global evaluation of reservoir islands

The study, led by Isabel Jones at the UK’s Stirling University, collated biodiversity data from 100 studies of reservoir islands — with time since habitat isolation ranging from 1 to 92 years — at 15 dams in North, Central and South America, Europe, and Asia.

In more than 75 percent of cases studied, dams had an overall negative impact on reservoir island species, affecting factors such as species population density, ecological community composition, and species behavior.

Thousand Island Lake in China, the result of a dam built in the 1950s on the Xin’an River, was one of 15 dams worldwide included in a recent study that concluded that reservoir islands should not be counted as conservation areas by developers. Photo by Bryan Ong on Flickr, under a Creative Commons CC BY-NC-ND 2.0 license

For as long as people have lived in the Amazon, turtles have likely been on the menu. But what was once low-impact subsistence hunting escalated dramatically after the arrival of Europeans. From the 1700s onward, demand for turtle eggs and meat skyrocketed. And the eggs weren’t just for eating: estimates suggest that more than 200 million eggs were harvested for both consumption and oil, fuelling lamps across Europe for two centuries.

This overexploitation led to such dramatic population declines that the Brazilian government eventually stepped in, launching the ambitious Amazon Turtle Program in 1979 — an on-going initiative that has so far protected 70 million turtle hatchlings across the Brazilian Amazon, with the intent of conserving vulnerable species.

But while that program continues to work toward a sustainable future for turtle populations —and for the people who still see chelonians as an important source of protein — three more recent threats loom over Amazonian turtle species: the illegal wildlife trade, widespread hydropower dam construction, and mercury contamination.

The Giant Amazon River Turtle (Podocnemis expansa) is the largest species of neotropical freshwater turtle, and is found throughout the Amazon basin. Overexploited for centuries, the species is making a comeback thanks to conservation initiatives. Photo courtesy of Camila Ferrara

An estimated 1,500 orangutans now live in rescue and rehabilitation centers located across Sumatra and Borneo. As habitat loss due to deforestation and forest fires continues, these institutions are struggling to keep up with demand.

Release into the wild is the ultimate, urgent, goal for most of these animals, but a new study warns that there could be serious genetic implications for the offspring of reintroduced animals — and orangutan populations in general — if those rescued from one region are released into a different region.

The study, led by primatologist Graham Banes, examined the genetic consequences when orangutans from different, divergent, subspecies interbreed. Borneo’s three recognized subspecies — from three distinct regions — are thought to have diverged from each other 176,000 years ago, meaning that hybridization between them may result in negative genetic effects. If hybrid offspring reproduce, combinations of genes that were beneficial for one lineage can be disrupted, resulting in poor health and reduced reproductive success, the researcher said. These effects, known as “outbreeding depression,” could threaten the survival of individuals and populations in the long-term.

Amazonia’s surge in hydropower development threatens numerous species with extinction, and puts unique habitats at risk, warns a recent study.

River dolphins, giant otters, turtles, fish, birds and monkeys will all have their habitats altered by hydroelectric dams, with some species likely to be completely wiped out, says an international team of biologists that looked at all impacts associated with 191 existing Amazon dams, as well as the 246 dams being planned or under construction.

What’s more, the researchers identified a network of negative interactions between dam construction, mining, climate change, human migration, and biodiversity and ecosystem services which illustrates how impacts can cascade in multiple, devastating ways.

In environmental terms, the most obvious and direct impact of dams reported by the study are on water flow and connectivity. Nutrients that flow downstream from the Andes are interrupted by dams; flood pulses that form a vital part of many species’ lifecycles are modified by the reservoirs and flow patterns that dams create and control; habitat complexity is lost; and species such as river dolphins become isolated in the stretches of river between hydropower developments, which leaves smaller sub-populations vulnerable to decline.

To read the full article, orginally published on Mongabay, click here.

River turtles in Colombia. Turtles, dolphins and otters are among the aquatic species threatened by dam construction, but risks extend to birds, bats and terrestrial animals too. Photo by Rhett A. Butler

Imagine a fish isolated in an Amazonian lake — part of the vast freshwater ecosystem of the Amazon basin, an ever-changing network of rivers, lakes and floodplains that extends to 1 million square kilometers (386,102 square miles).

Now imagine that isolated fish as water levels rise during the wet season, and floodplains vanish beneath up to 15 meters (49 feet) of water. The fish — once restricted by the lake’s edge — swims freely into the flooded forest and mingles with others of its kind from elsewhere.

For thousands of years, isolated fish populations across the Amazon have likewise played a game of musical chairs: intermixing between flooding water bodies, migrating short and vast distances between lakes and along river channels, and then as the waters receded, forming new lake and river populations.

This connectivity — with the genetic mixing it affords — is vital for healthy fish populations, but is extremely vulnerable to changes in the annual “flood pulse” that inundates forests.